there isn't a 'best' gaming console per se..each and everyone is different, and caters for different people. the wii is good to play on with your family where as the 360 and ps3 are 'maturer' consoles where you'd get a variety of games.
if u want a console purely for gaming go for the 360. it has tones of a++++ games, and a larger catalog of games overall over the ps3. online is much better as well but you have to pay for it. you get what you pay for. it is cheaper than the ps3. if you want to play online over wireless, you have to purchase all of that separately.
if you want to watch BR movies etc and want to play games as well then go for the ps3. it's an all round media system. where as the 360 is mainly for games, although you can watch HD-DVD's on there. online is free on the ps3 but not as good as 360's. wi-fi is built in which is a bonus.
GTA4 is available on both consoles but the 360 has extra content which is downloadable at a price (MS points). NFS is available on both consoles too.
PS3 if you have got cash to spend...on games and blue-ray disc and if you have a big HD Tv.
Blue ray movies and games on bigg tv are a treat on the ps3.
Plus God of war 3 is coming out. Best most brutal game ever.
Exclusives are better on PS3. Any good game on the 360 is either on the pc or ps3. PS3 exclusives are only on PS3 like Uncharted, killzone 2 and God of war 3.
360 has more content for games as downloads for which you pay but i doubt you will want to spend extra on game content unless you are a hardcore games.
On the other side if you want to save money...you can just buy a 360 ...mod it and download games.....
Plus for 360 you have to buy a wireless adpater for online and you can only buy harddrive frm microsoft ...whereas ps3 you can put in any compatible hardrive even from a third party and it comes with wireless right out of the box....and it has a internet browswer..something the 360 doesnt have.
But what 360 has is u can listen to songs while playing games through usb but u cant do this on the ps3.